[A/N:I really don't want to drag the Andal invasion,since I want to get to the Valriyan rise and Doom,after that Aegon the Conquers conquest are al not going to be too long.Since I have see many lose interest,when I take too long.]
In the South men were armed with weapons made of bronze, but the Andals had weapons made of iron and steel weapons,so the First men of the south wasn't able withstand the armored shock cavalry assaults of the Andals' knights.
As the Andals conquered the kingdoms of southern Westeros, they aggressively stamped out the worship of the Old Gods of the Forest by the First Men they conquered, and forced them to convert to their worship of the Seven-faced God.
But they didn't fully succeed in this, as The North defeating Andal Army left a doubts,because the Andals had bragged about how there god showed them the vision of them successfully conquering Westros.
Now if this was just one defeat and just in Moat Catlin,they could say it was because of Strategic location they lost,but Andal army lost multiple times to the North and Middle Earth army.
No matter how much Andal Army tried they couldn't defeat Eragon or North army,it also didn't help when Andal's were pushed back to such extent and the multiple defeat led their religion try Faith of the Seven to be questioned.
The ones that did was House of Garder was now interested in the so called new allies of the North,Darius Gardner was the leader of Reach and he was able to meet with Elves and Eragon once,so he was warned about the Andals,which is how he was able to negotiate with the Andal and turn them against there own.
Also with time Andal's gave up trying to conquer North,since it was doing more bad than good.
Still Warsnand Rebellions would continue in later centuries against other kingdoms in Westeros such as the Kingdom of the Vale, but by that point, the Andals had intermingled with the local First Men so much that they stopped being seen as distinct groups, and such conflicts just faded into local politics, no longer considered "invasions".
The so called concepts of "knighthood", producing elite warriors known as "knights" who wore full suits of iron armor while riding into battle on heavy horse. The related concept of "chivalry" spurned on the knights, a code of knightly was introduced with time even North decided to take on some of these concept,but without letting any religious themes getting in.
During this time Interestingly none of Eragon's Special summons died like Durin and Telchar was still alive and in their prime.
Eragon because of the war once again gained more SP than before,so summoned the great animals from LOTR which are Great Eagles,that included Thorondor,who was the greatest of all the Eagles in terms of size, with his wingspan measuring at 30 fathoms (180 feet or nearly 55 meters).Gwaihir and his brother Landroval was descended from Thorondor, the greatest Eagle who ever lived.There was whole big groupt of them.
The Next was Griffin with the head and talons of an eagle, and the body of a lion, with equine-like ears. Most appear the same as one another, covered with feathers that are golden-brown coloured, and yellow beaks with a black tip at the end.
These two were mainly summoned for creating aerial a new aerial unit.
Then Mearas were a breed of wild horses in the north of Middle-earth. They surpass normal horses in intelligence, speed and strength. According to lore, the ancestors of the Mearas were brought from the West by Orome.These were mainly for Cavalry
Lastly the War Goats which are used for riding by Dwarves,they are fast and powerful.
So a Century passed by New Stark Lord took control and Eragon once again saw the death of his friends,it was sad and weary thing to go through,Just then Aule warned him about a Dragon Lairing.
Galadriel had used her ability to see the future and warned Eragon"Do not take everything from them,since Valyrians are very much involved in the future."
Eragon didn't understand what she meant at the time,but only in the future did he understand Galadriel meant one or two of his wives would be Targaryens.